In the manufacture or production of endless printing bands, for example, of the type disclosed in U.S. Pat. No. 3,977,321 which issued to the Assignee of the present invention, it is common to mold a wide endless band with laterally extending rows of raised characters, for example, by using a compression mold and a flat core blade as disclosed in U.S. Pat. No. 3,418,929. The mold provides the wide endless band with raised printing characters on one side of the core blade and with corresponding raised visually readable characters on the opposite side of the core blade. The visually readable characters are formed by applying a coating of color contrasting or white paint-like material to the corresponding side of the wide endless band, and then the coating is wiped or removed from the outer surfaces of the raised characters so that each character is clearly readable on the light or white background formed by the coating.
The wide endless band is then cut or slit at laterally spaced intervals to form a plurality of narrower endless bands. Preferable, the wide endless band is reinforced by an internal reinforcing cord or filament which is wound on the flat core blade before the compression molding operation, for example, as shown in above U.S. Pat. No. 3,418,929.
In the process of wiping the color contrasting or white material from the outer surfaces of the molded characters to form the visually readable characters, it is difficult to assure that the coating is removed only from the outer surfaces of the raised characters and not from the adjacent background or relief areas. This problem is particularly serious when the band is only partially filled with raised characters on each side of the core blade and a portion of the wide endless band has no molded raised characters. If the coating is inadvertently removed from the background area, the band usually becomes scrap material.
There is also a problem encountered when cutting the wide endless band into a plurality of relatively narrower endless bands after the visually readable characters are formed. That is, the wide endless band is usually slit by a row of cutting saws or knives after the wide endless band is mounted or pulled onto a rotatable cylindrical arbor. Thus it is important that the wide endless band be precisely located on the arbor relative to the row of adjacent slitting saws or knives. If the wide band is not precisely located on the arbor relative to the slitting knives, the peripherally spaced characters on each narrow band are not located uniformally relative to the opposite edges of the band, with the result that scrap bands are produced.